The present invention relates to a device for a suspended cealing structure for rectangular filter elements, wherein at least some filter elements are located at a distance from each other in order to allow therebetween the suspension of objects such as light fittings or the like from the suspended ceiling structure and in addition an air stream is arranged to flow out through the filter elements and downwards towards the floor.
Suspended ceiling structures of the above mentioned type are above all used in clean rooms in which turbulence problems caused, for instance by light fittings, has caused great problems, since particles are captured and forced to circulate within a region immediately below the lamp, so that they can spread uncontrollably in the room. It has been established that in a room with a laminar air flow from the filter element downwards towards the floor, turbulent regions are produced below the light fittings down to a distance from the fitting of approximately three times the width of the fitting. This means that all particles produced in the region flow back upwards towards the ceiling and are mixed with the clean filtered air, whereby the cleanness of the whole room will be heavily impaired.
Until now these problems have been solved by providing a suspended ceiling consisting of a great number of small tubes of plastics or glass material, which are placed on their ends to form a continuous body and the suspended ceiling is composed of these bodies which thereby prevent the occurrence of turbulent regions below the light fittings. However, this solution is extremely expensive as far as the material and the installation is concerned and the object of the present invention is to provide a structure which completely eliminates the need for an extra suspended ceiling and at the same time efficiently prevents the occurrence of turbulent regions below the light fittings or other objects suspended from the ceiling.